John Mahoney, the actor best known for playing Martin Crane on Frasier, died on February 4 at 77 years old, after suffering from throat cancer. Now, one of Mahoney’s TV sons, Kelsey Grammer, has paid a poignant tribute to his former costar.

Grammer, who played Frasier Crane, opened up on The Talk Wednesday about Mahoney, and how he acted as a surrogate father to him when they were filming Frasier. “Somebody asked me to write a statement, you know, for Twitter. I don’t really Twitter, I don’t tweet, necessarily, but I have somebody who will do a tweet for me once in a while. So I just had them say, ‘He was my father, and I loved him,’” Grammar said, tearing up.

“John actually played my father longer than I knew my own father, so he was more like my dad,” Grammer said. “I had the same relationship with David Hyde Pierce as my brother, because I didn’t really have a brother, either. So it was an interesting thing that we got to explore what it would heave been like to have those relationships. I miss him.”

Their Frasier costar, Peri Gilpin, also echoed the sentiment that the cast was like a family. On Twitter, she posted a photo of Mahoney singing at her wedding. She also reminded fans that Mahoney's career encompassed far beyond Frasier. “Watch Moonstruck, Say Anything, and/or Frasier or anything you can with him in it and raise a glass to John,” she wrote. “Remember him well.”

John singing at my wedding. Watch Moonstruck, Say Anything and/or Frasier or anything you can with him in it and raise a glass to John. Remember him well. pic.twitter.com/Tj3i5B4x13